The Sibling Effect

For many, the sibling relationship is the longest lifetime relationship, lasting decades longer than parent-child or spousal relationships. This lifelong history of shared family experiences can influence whether sibling relationships are characterized by intimacy and closeness or rivalry and distance. Sibling experiences can contribute positively or negatively to how children think about themselves and their social or emotional adjustment.

Aidan McGee, 19, is 18 months younger than his sister. “She looked out for me and even talked for me when we were really little,” he says of his sister. “When we were in high school, she would give me rides before I got my license. Later, our parents were more protective of her and gave me more independence just because she was a girl and I was a boy.”

McGee’s comments highlight the view that perceptions of unfair parenting, age and gender differences can influence sibling relationships.

Different, But Equal

As early as toddlerhood, children may recognize parents’ “fair” and “unfair” treatment between siblings. Parents’ unequal treatment of siblings can strain already competitive sibling relationships, increase sibling conflict and children’s disruptive negative attention seeking behavior.

Children who feel that parents treat siblings unequally perceive the family environment differently. This view can weaken the important sibling bond of shared family history and threaten sibling relationship quality across time.

However, equal parenting is not always an option—age, gender, personality and responsibility characteristics sometimes necessitate different parenting among siblings.  Parents should take heart: If siblings perceive parental treatment as “fair,” despite being different, it may actually promote their sense of uniqueness and individuality, thereby decreasing sibling conflict.

Siblings Across Development

The closeness and quality of sibling relationships changes across child development. In early childhood, same gender siblings may share more interests and similarities, which can serve, in equal amounts, to promote closeness or competition. While boy-girl sibling pairs may share fewer commonalities in early childhood, research suggests that by late adolescence their relationship may be stronger than gender matched sibling pairs.

However, regardless of gender similarity, siblings may drift apart during early and middle adolescence when youth focus on developing autonomy from the family through focus on friendship and early romantic relationships.

Sibling Conflict: The Good and Bad

By // Erin Lanphier, Ph.D.